This paper analyzes the existence of Hopf bifurcation and establishes the conditions under which the equilibrium path converges toward periodic solutions in a one-sector optimal growth model with delay. We establish the limits and the possibilities of nonlinear dynamics (i.e., cycles) vis-à-vis delays. In particular, we formulate a new method to further comprehend the root distribution of the characteristic equation of a standard optimal growth model with delayed investment structure. We show that nonmonotonic dynamics (limit cycles, persistent oscillations) occurs when the delayed investment causes permanent adjustment failures among the economic variables in the economy.

How much can government-driven mortgage modification programs reduce the mortgage default rate? I compare an economy without a modification option to one with easy modifications, and evaluate the impact of these loan modifications on the foreclosure rate. Through loan modification, mortgage servicers can mitigate their losses and households can improve their financial positions without having to walk away from their homes. When modifying loan contracts is prohibitively costly, the default rate increases 1.5 percentage points in response to a 2007-style unexpected drop in housing prices of 30%. I calibrate the cost of modification after the financial crisis to match the Home Affordable Modification Program (HAMP) modification rate of 0.68%. My quantitative exercises show that current government efforts to promote mortgage modifications reduce the mortgage default rate by 0.63 percentage points.

The existing literature dealing with mutual interactions between the extent of oil dependence and the possibility of belief-driven fluctuations unanimously ignores international loans. This simplified assumption disregards the fact that the relative magnitude of the financial account and the trade account exhibits an increasing trend. Faced with this deficiency in the literature, this paper develops a real business cycle model featuring oil dependence in domestic production and international loans, and examines whether both the presence of international borrowings and the dependence on imported energy will govern the emergence of belief-driven fluctuations.

A nonlinear programming formulation is introduced to solve infinite-horizon dynamic programming problems. This extends the linear approach to dynamic programming by using ideas from approximation theory to approximate value functions. Our numerical results show that this nonlinear programming is efficient and accurate, and avoids inefficient discretization.

This paper investigates, in the case of the euro area, the standard assumption that the liquidity trap steady state, which arises from the existence of the zero lower bound on the nominal interest rate, is locally unstable. We show that the policy function of the European Central Bank (ECB) is described by a nonlinear Taylor rule. Then, using our estimations, we show that around the liquidity trap steady state the equilibrium is locally determinate for most plausible parameter values. Finally, we find that an inflation shock is more efficient than a demand shock to escape the liquidity trap steady state.

We provide a theory-based inquiry into the contours of China's international balance sheets after the renminbi becomes convertible under the capital account. We construct a two-country general equilibrium model with trading in equities and bonds and calibrate the model with U.S. and Chinese data. We interpret Chinese capital account liberalization as a removal of restrictions that prohibit agents trading Chinese bonds and U.S. equities. We explore how international risk-sharing can be achieved through portfolio diversification in each of these asset market configurations. We also look at how these holdings would change as China gradually rebalanced its production with a larger share of labor income, and as the productivity gap between China and the United States narrowed. We find that both U.S. and Chinese residents would have incentives to increase their holdings in each other's equities and to issue debt in each other's currency.

In a two-period overlapping-generations model with production, we consider the damaging impact of environmental degradation on health and consequently life expectancy. Despite the presence of social constant returns to capital, which would otherwise generate unbounded growth, when pollution is left unabated, the economy cannot achieve such a path. Instead, it converges either to a stationary level of capital per worker or to a cycle in which capital per worker oscillates permanently. The government's involvement in environmental preservation proves crucial for both short-term dynamics and long-term prospects of the economy. Particularly, an active policy of pollution abatement emerges as an important engine of long-run economic growth. Furthermore, by eliminating the occurrence of limit cycles, pollution abatement is also a powerful source of stabilization.

We present a model capable of explaining 200 years of declining fertility, 200 years of rising educational achievement, and a significant baby boom for the United States and twenty other industrialized market countries. We highlight the importance of secularly declining young adult mortality risk for producing secularly declining fertility and a sudden decline in housing costs after the end of the Second World War, but ending by 1970. In addition, we introduce a new puzzle for the profession: Given the magnitude of the Baby Boom, roughly equal to fertility in 1900 for many of these countries, why did schooling of the Baby Boom cohorts not fall to the 1900 level of their predecessors? In fact, not only did it not fall, but the schooling levels of these cohorts are higher than for previous cohorts. Using a quantitative model, we are able to identify the magnitude of the reduction in costs of education necessary to explain this paradoxical increase in schooling. We produce a novel data set on historical education expenditures with over 1,500 observations. We find empirical support for these cost reductions.

Historically, industrialization has been associated with falling relative returns to skills. This fact is at odds with most unified theories of industrialization, which tend to imply rising skill premia as natural concomitants of economic growth. This paper develops a very simple model of historical growth to help solve this puzzle. Assuming that human capital is both a consumption good and an investment good, the model demonstrates how gradually rising investments in human capital, nonmonotonic fertility rates, and falling skill premia can all be explained within one theory.

According to empirical studies, the life cycle of labor supply volatility exhibits a U-shaped pattern. This may lead to the conclusion that demographic change induces a drop in output volatility. We present an overlapping-generations model that replicates the empirically observed pattern and study the impact of demographic transition on output volatility. We find that the change in age composition itself has only a marginal influence on output volatility, as the mitigating effect of more individuals with lower labor supply volatilities is compensated for by higher age-specific labor shares. Instead, the driving force behind the Great Moderation in our model is the downward shift of the age-specific labor supply volatility curve.

We build a model of search and matching in which agents trade using coins that are imperfectly recognizable, but have access to a coin inspection technology—known as coin assaying—that reveals the intrinsic content of coins for a fee. We consider two sources of imperfect information: counterfeit coins and clipping. With counterfeits, coin assaying reduces the extent of inefficiencies associated with imperfect recognizability of coins (namely lower traded quantities and lower trading frequencies). Yet coin assaying does not necessarily increase welfare, because it unmasks counterfeits that then trade at a discount, reducing total output. With clipping, we show that agents clip for two reasons: in the hope of passing an inferior coin for a superior one, and to reduce the purchasing power of coins that are too valuable. Although coin assaying could remove the first type of clipping, it had no effect on the second.

We investigate the international linkages of uncertainty associated with the long-term movements of inflation. In the first step, we establish that inflation uncertainty in the G7 is intertwined, and the degree of synchronization has increased during the recent two decades. We also document a rise in inflation uncertainty accompanying the global financial crisis. Based on a factor–structural vector autoregression, we provide evidence of a common international shock. We disclose that this shock is closely related to oil and commodity price uncertainty, and it explains large parts of the recent rise in inflation uncertainty. Moreover, increased synchronization can be explained by greater relative importance of this global shock. We also document that inflation uncertainty has become more stable, because domestic shocks translate less extensively into individual economies. This finding lends support to the “good policy” hypothesis.

We estimate the effects of anticipated and unanticipated monetary policy changes on jump variation by employing high-frequency nonparametric jump detection methods. We find that anticipated changes in the Fed funds have no significant effect on jumps. In contrast, jump variation in the price of financial market data increases with monetary policy surprises. We document evidence of asymmetries in the response of jumps to monetary policy changes. Monetary policy surprises and positive changes in the Fed target rate induce increments in jumps. Similar results exist in the sector analysis. In addition, this study uncovers no evidence of endogenous response between jumps and monetary policy surprises.

This paper investigates how the different food aid programs affect economic development via their effect on the parental trade-off between the number of children and the investment in each child's human capital. This is done in an OLG framework where parents decide on the number of children and the nutrition and secondary schooling of each child. Primary schooling is mandatory. Providing school meals locks countries with no children attending secondary schooling into poverty by reducing the private (nutrition) cost per child. In countries where parents find it optimal to enroll children in secondary schooling, food aid increases the marginal benefit of schooling. Consequently, school feeding programs are conducive to economic development in these countries. If food aid is in the form of a food price subsidy, we show that child nutrition and thus children's human capital increase unambiguously. Although fertility and schooling are not directly affected, a sufficiently high subsidy rate will induce parents to begin to enroll children into secondary schooling by the assumed complementarity between nutrition and schooling in the human capital production function. If the food aid program provides a fixed amount of food per child, this decreases the marginal benefit of parental nutritional investments; therefore, it leads to higher fertility and to lower total provision of nutrition per child.

The Hodrick–Prescott filter represents one of the most popular methods for trend–cycle extraction in macroeconomic time series. In this paper we provide a multivariate generalization of the Hodrick–Prescott filter, based on the seemingly unrelated time series approach. We first derive closed-form expressions linking the signal–noise matrix ratio to the parameters of the VARMA representation of the model. We then show that the parameters can be estimated using a recently introduced method, called “Moment Estimation Through Aggregation (META).” This method replaces traditional multivariate likelihood estimation with a procedure that requires estimating univariate processes only. This makes the estimation simpler, faster, and better behaved numerically. We prove that our estimation method is consistent and asymptotically normal distributed for the proposed framework. Finally, we present an empirical application focusing on the industrial production of several European countries.

Economic and social impacts of aging trends will be of the utmost importance in the near future. We embed a stylized pay-as-you-go (PAYG) pension system into a DSGE model with overlapping generations to assess the macroeconomic effects of aging in a small Euro Area economy. The simulations suggest large negative impacts on GDP and private consumption. In addition, external imbalances may widen significantly under the PAYG system. All results are conditional on the policy options addressing debt sustainability–the impacts tend to be very large if the government finances the aging with higher social security premia instead of lower replacement ratios. Sensitivity analysis reveals that GDP and private consumption impacts are less robust than those on external imbalances. Results also imply that supranational policy coordination may be crucial if the objective is to preserve economic and financial stability in the Euro Area.

This paper analyzes the role of money and monetary policy as well as the forecasting performance of New Keynesian dynamic stochastic general equilibrium models with and without separability between consumption and money. The study is conducted over three crisis periods in the Eurozone, namely, the ERM crisis, the dot-com crisis, and the global financial crisis (GFC). The results of successive Bayesian estimations demonstrate that during these crises, the nonseparable model generally provides better out-of-sample output forecasts than the baseline model. We also demonstrate that money shocks have some impact on output variations during crises, especially in the case of the GFC. Furthermore, the response of output to a money shock is more persistent during the GFC than during the other crises. The impact of monetary policy also changes during crises. Insofar as the GFC is concerned, this impact increases at the beginning of the crisis, but decreases sharply thereafter.

We compare model forecast error statistics with forecast error statistics of professional forecasts. We look at a standard sticky-prices–wages model, concluding that it delivers too strong a theoretical forecastability of the variables under scrutiny, at odds with the data (professional forecasts). We argue that the lack of compatibility between the model and professional forecasts results from trying to fit inflation (which is probably nonstationary) to a model that assumes inflation is stationary. A modified version of the model, one with a varying inflation target, delivers a better fit in terms of forecastability.

This paper focuses on the macroeconomic and wealth effects of unconventional monetary policy. To this end, we estimate a Bayesian structural vector autoregression (B-SVAR) using U.S. monthly data for the post-Lehman Brothers' collapse period. We show that a positive shock to the growth rate of central bank reserves does not have a substantial impact on industrial production or consumer prices. However, it also gives a strong boost to asset prices, which is larger in magnitude for stock prices than for housing prices. Thus, unconventional monetary policy typically operates via portfolio-rebalancing effects. A VAR counterfactual exercise confirms the role of the shocks to the growth rate of central bank reserves in explaining the dynamics of the variables included in the system, especially in the case of asset prices. Finally, additional empirical assessments uncover an important change in the conduct of monetary policy from “standard” to “exceptional” times and the suitability of our model to capture such a structural transformation.

In sticky price models based on micro evidence that each period a fraction of prices are kept unchanged, recent studies reach the qualitatively equivalent conclusion that higher trend inflation is a more serious source of indeterminacy of rational expectations equilibrium, regardless of whether labor is firm-specific or homogeneous. This paper shows that the model with firm-specific labor is more susceptible to indeterminacy induced by high trend inflation than the model with homogeneous labor, because these two different specifications of labor lead to distinct representations of inflation dynamics. In addition, the model with firm-specific labor is more susceptible to expectational instability of the equilibrium caused by high trend inflation.